Line two cookie sheets with nonstick liners and lightly grease. Put the colored sugars in separate shallow bowls.
Pour 3/4 cup of the water into bowl of a heavy-duty mixer fitted with whisk attachment and sprinkle the gelatin over the water. Let sit until the gelatin is moist and plump, about 5 minutes. Add the vanilla bean seeds and salt. (They’ll stay on top of the gelatin for now.)
Put the remaining 1/2 cup water, the sugar, and corn syrup in a medium heavy saucepan. Cook, stirring, over low heat until the sugar dissolves. Set a candy thermometer in the pan and increase the heat to high and bring to a boil. Boil, without stirring, until the hot syrup is 258°F.
With the mixer on medium-low speed, slowly pour the hot syrup into the gelatin mixture in a thin stream down the side of the bowl (avoid pouring syrup onto the whisk, as it will splash against the sides of the bowl). Gradually increase the speed to medium-high and beat until the mixture is very thick, about 10 minutes. The outside of the bowl will still feel quite warm. It’s important to work with the marshmallow while it’s still warm—it’s difficult to pipe when it’s cold and stiff.
Fit a large round tip 1/2- or 2/3-inch (I use an Ateco #5 or #7) into a pastry bag and fill the bag with some of the marshmallow. Pipe the marshmallow into 3-inch-long by 1-inch-wide logs, spacing them about 1 inch apart on the prepared cookie sheets. As you reach the end of a log, keep pressure on the bag and in one continuous motion, lift the pastry tip up and pipe more marshmallow on top of the log going back about 1 inch. Release any pressure on the pastry bag and pull the tip up and out to form a beak. Reload the pastry bag with marshmallow as needed.
Sprinkle each shape with colored sugar, using your fingers to pat the sugar onto the marshmallow to cover almost completely, then set the cookie sheets aside until the shapes are completely cool but still tacky, about 1 hour. Using your fingers and working with one marshmallow at a time, lift the marshmallows from the sheets and roll in the bowl of colored sugars, pressing the shapes into the sugar lightly to cover completely. Return the shapes to the same sheets. Dap a bit of the remaining marshmallow from the bowl onto the flat side of the mini chocolate chips and press onto the shapes to form “eyes.” Set the sheets aside until the marshmallows are completely cool and no longer tacky, about 2 hours. Stow in an airtight container for up to 1 week.